By Helen Chow, ND, Dip Herb, UK-qualified Naturopath & Herbalist, Food Therapist
Originally published January 11, 2018. Reviewed & Updated: September 10, 2026
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Have you ever had a blood test, been told that your blood sugar is “fine”, and gone home thinking: “Great. That’s one thing I don’t have to worry about…”
Ii’s completely understandable. And sometimes it really is good news.
But sit down with me for a moment, because there is another part of the blood-sugar story that I think every woman should understand — particularly as we move through our 50s, 60s and beyond.
Your glucose can look perfectly respectable. Your HbA1c can look reassuring. And yet your body may be working much harder than you realise to keep those numbers looking good.
The missing character in our story is insulin. And once you understand that, blood-sugar testing starts to make much more sense.
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First, Let’s Go Back To HbA1c
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We’ve already talked about HbA1c in our HealthSifu article on healthy blood sugar.
Think of HbA1c as your three-month blood-sugar story. Glucose circulating in your bloodstream can attach itself to haemoglobin, the oxygen-carrying protein inside your red blood cells. This attachment is called glycation.
The more glucose your red blood cells have been exposed to, the more haemoglobin tends to become glycated.
Because red blood cells live for several months, HbA1c gives us an indication of your average glucose exposure over roughly the previous 8–12 weeks.
Very useful, indeed. But here’s the important bit:
HbA1c measures the glucose side of the story. It doesn’t tell you how much insulin your body needed to produce to achieve that result.
And that totally changes the conversation.
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Imagine Two Women Sitting At My Kitchen Table…
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Let’s call them Jane and Susan. They both have a fasting blood glucose of 5.0 mmol/L. On paper, their glucose looks exactly the same.
But suppose we also measure their fasting insulin:
Susan’s fasting insulin is: 4 µU/mL
Jane’s is: 16 µU/mL
Now we have learned something that the glucose result alone couldn’t tell us: Jane is producing approximately four times as much fasting insulin as Susan while maintaining the same fasting glucose.
That doesn’t automatically diagnose Jane with a disease. But wouldn’t you want to know that?
I certainly would!
Because it tells us that looking only at glucose can leave part of the metabolic picture hidden.
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Why Would The Body Make More Insulin?
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Insulin is one of the body’s essential hormones.
After you eat, particularly foods containing carbohydrate, glucose enters your bloodstream. Your pancreas releases insulin, which helps your cells take up and use or store nutrients and helps regulate blood glucose.
But sometimes tissues become progressively less responsive to insulin. This is what we mean by insulin resistance.
Your wonderfully clever body doesn’t immediately give up and allow your blood sugar to shoot through the roof. It compensates.
The pancreas can produce more insulin to help maintain glucose within an acceptable range. For a time, that compensation may work rather well. So you can potentially have:
Increasing Insulin Resistance —> More Insulin Being Produced —>
Blood Glucose Still Being Controlled —>HbA1c Still Looking Reassuring
That is the part we need to remember:
Normal glucose doesn’t necessarily tell us how much work went into keeping it normal.
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So How Can We Look At Insulin?
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One relatively simple measurement is fasting insulin.
Just as fasting glucose tells us what your glucose is doing after an overnight fast, fasting insulin tells us how much insulin is circulating at that point.
If we have both fasting glucose and fasting insulin, we can go one step further. We can calculate something called HOMA-IR. Don’t be put off by the name. It sounds much more complicated than the idea behind it.
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Meet HOMA-IR — Without The White Coat
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HOMA-IR stands for: Homeostatic Model Assessment of Insulin Resistance. That’s quite a mouthful!
In simple terms, HOMA-IR uses your fasting glucose and fasting insulin together to estimate insulin resistance.
The original calculation, when glucose is measured in mmol/L, is:
Fasting insulin × fasting glucose ÷ 22.5
Now, let’s return to our two imaginary women.
Susan
- Fasting glucose: 5.0 mmol/L
- Fasting insulin: 4 µU/mL
- HOMA-IR:
4 × 5 ÷ 22.5 = approximately 0.9
Jane
- Fasting glucose: 5.0 mmol/L
- Fasting insulin: 16 µU/mL
- HOMA-IR:
16 × 5 ÷ 22.5 = approximately 3.6
Same fasting glucose. Very different fasting insulin. Very different HOMA-IR.
Suddenly we can see why this so interesting.
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Does That Mean Everyone Should Diagnose Themselves From Their HOMA-IR?
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No. And this is important…
Please don’t find an internet chart, calculate your HOMA-IR and decide that a decimal point has diagnosed you with insulin resistance.
HOMA-IR is an estimate, not a stand-alone diagnosis. There isn’t one universally accepted HOMA-IR number that separates every insulin-sensitive person from every insulin-resistant person. Results can vary according to the population being studied, the laboratory insulin assay and other factors.
There is also an updated computer model called HOMA2, developed from the original HOMA model.
So, take HOMA-IR as another clue in the metabolic detective story, rather than a magic number. Your result needs context.
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HbA1c versus HOMA-IR — Which One Wins?
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Neither. They’re answering different questions.
Think of them like this:
HbA1c asks:
How much glucose have my red blood cells been exposed to over the past couple of months?
Fasting glucose asks:
What is my blood glucose doing right now, after fasting?
Fasting insulin asks:
How much insulin is circulating in my fasting state?
HOMA-IR asks:
When we look at fasting glucose and fasting insulin together, what might they suggest about insulin sensitivity?
That’s why you don’t need to choose between HbA1c and HOMA-IR. It’s better to understand what each one can — and cannot — tell us.
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Your HbA1c Isn’t Useless — Far From It…
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We don’t want you walking away thinking: “Well, HbA1c isn’t any good.”
Absolutely not. HbA1c is extremely useful. It is an established clinical test used to assess longer-term glucose exposure, identify people at high risk of type 2 diabetes and, in appropriate circumstances, diagnose diabetes.
In the UK, an HbA1c of 42–47 mmol/mol (6.0–6.4%) is considered a high-risk range for developing type 2 diabetes.
An HbA1c of 48 mmol/mol (6.5%) or above can indicate diabetes, although in someone without symptoms this normally requires confirmation with another test.
If you want those numbers explained more fully, go back to our HealthSifu blood sugar guide.
The point isn’t to throw HbA1c away. It’s to understand that HbA1c doesn’t measure insulin.
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And HbA1c Has Another Little Wrinkle
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Remember that HbA1c depends upon your red blood cells. That means certain conditions affecting haemoglobin or the lifespan of red blood cells can affect the result.
Iron-deficiency anaemia, substantial blood loss, haemolytic anaemia, some haemoglobin variants and some kidney-related circumstances are among the situations in which HbA1c may need particularly careful interpretation.
So once again: One number is rarely the whole person.
That’s something we should remembered more often in the health arena.
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What Would I Want to Know About My Metabolic Health?
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Rather than becoming obsessed with one “perfect” number, it is good to look at the pattern.
Depending on your individual circumstances and what your doctor or healthcare professional considers appropriate, that conversation might include:
- HbA1c
- Fasting glucose
- Fasting insulin
- HOMA-IR
and then the wider metabolic picture — perhaps
- triglycerides
- HDL cholesterol
- blood pressure
- waist measurement
- body composition
And, of course, we would want to know about you.
- Has your waist changed?
- Are you constantly hungry?
- Do you become sleepy after meals?
- Has losing fat become surprisingly difficult?
- Have your triglycerides changed?
- Are you losing muscle?
- What are you actually eating?
- How are you sleeping?
- How active are you?
- What has happened in your life over the past year?
A laboratory result is valuable information. It isn’t your entire metabolic story.
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Why This Matters Particularly after 50
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This is where our conversation becomes much bigger than diabetes and becomes a question of your overall metabolic health.
After 50, we don’t want to be thinking merely about avoiding a diagnosis. We MUST think about maintaining muscle, metabolic flexibility, strength, mobility, independence and a body capable of carrying us enthusiastically into the decades ahead.
That’s why my HealthSifu article on healthy ageing focuses on a life we actively build rather than ‘Things” that simply happen to us.
Finding metabolic changes earlier gives us something enormously valuable: T I M E !!!
- Time to examine our food.
- Time to build muscle.
- Time to move more.
- Time to improve sleep.
- Time to address chronic stress.
- Time to talk to our healthcare professionals.
- Time to make smarter choices before today’s small metabolic wobble becomes tomorrow’s much bigger problem.
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So The Next Time Someone Says, “Your blood sugar is fine…”
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Be pleased !!! Yay!!!
But you can also be curious. You might ask:
- What was my HbA1c?
- What was my fasting glucose?
And, where appropriate, ask:
- Would fasting insulin add useful information to my particular situation?
You don’t need to become your own endocrinologist. You don’t need to chase an “optimal” number somebody announced on social media.
And you certainly don’t need to become frightened of food. You simply need to understand that glucose is one part of a conversation between glucose, insulin, your tissues, your pancreas and your metabolism.
Sometimes the numbers on the surface look beautifully calm while underneath, your body is paddling furiously to keep them there.
And that is precisely why looking a little deeper can sometimes be very, very worthwhile!
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A HealthSifu Note
This article is for education and is not intended to diagnose or treat insulin resistance, prediabetes or diabetes. Laboratory results need to be interpreted in the context of your health, medications and individual circumstances. If you’re concerned about your glucose, insulin or diabetes risk, discuss appropriate testing and interpretation with your doctor or qualified healthcare professional.
HealthSifu
Make Smarter Choices. Consciously. Deliberately.
Scientific References & Further Reading
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HbA1c Basics — NICE explains that HbA1c reflects average plasma glucose over approximately the previous 8–12 weeks and does not require fasting.
UK Ranges — NICE guidance identifies HbA1c 42–47 mmol/mol (6.0–6.4%) as its high-risk range and 48 mmol/mol (6.5%) or above as indicating possible type 2 diabetes, subject to appropriate confirmation.
Original HOMA — Matthews DR et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28:412–419.
HOMA Research — Oxford Diabetes Trials Unit provides the research history and publications behind HOMA and its later development.
HbA1c Limitations — The NGSP explains how altered red-cell survival, iron-deficiency anaemia, haemoglobin variants and other circumstances can affect HbA1c measurement or interpretation.
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